1. Field of the Invention
The present invention relates to a heat dissipating silicone grease composition, preferably the invention relates to a heat dissipating silicone grease composition having excellent coating properties.
2. Description of the Prior Art
Electrical and electronic parts generally generate heat, and the heat needs to be removed for electrical parts to function properly. A variety of heat dissipating thermally conductive materials have been proposed, and they are available in two forms: (1) sheets that are easy to handle and (2) pastes commonly referred to as heat dissipating greases.
The heat dissipating greases mentioned above offer the advantages of being able to fill irregular surfaces and crevices in electronic parts and enlarging the contact area between electronic parts and the heat dissipating materials. However, the heat dissipating greases are difficult to handle and are ordinarily used after packing them into dispensing device syringes. In addition, the use of a printing process referred to as a metal screen or stencil printing process can efficiently and accurately apply a heat dissipating grease when the grease is to be coated on a relatively large area such as a heat sink. Various types of silicone greases have been developed to be used as such heat dissipating greases. (For example, see Unexamined Japanese Patent Publication No. 2000-63872, No. 2000-63873, No. 2000-109373, No. 2000-114438, No. 2000-129160, No. 2003-301189.)
However, the printing process described above involves an application of a heat dissipating grease on a heat sink and the like by spreading it using a squeegee and the like on a metal sheet made of stainless steel and the like cut into a desired shape. And a problem is that the grease is difficult to apply when the heat dissipating grease is highly viscous. The problem is particularly severe when the amount of a thermally conductive filler in a heat dissipating grease needs to be increased to improve the thermal conductivity of the heat dissipating grease and the viscosity rises due to the increase of the filler. Therefore, the development of a heat dissipating silicone grease composition having excellent thermal conductivity that can be applied on metal screens and the like using a printing process is urgently needed.